A munitions fuze must provide proper weapon system operation as well as be reliable in order to safely manufacture, store and use. Generally, the fuze must insure that there is no possibility of main warhead initiation until the munition is actually on its way to the target.
A part of every fuze device is the safety and arming (S&A) device; the function of which is to prevent the arming of the fuze until a specific set of conditions are met. This is accomplished by sensing arming environments, maintaining firing train safety and initiating the explosive train. Additionally, many S&A devices provide fuze timing functions for safe separation, arming, and firing delay.
Many S&A devices utilize setback acceleration as the sensed arming environment. Examples of prior devices used to detect and integrate the setback acceleration environment include G-weight driven escapements, successive falling leaves, zig-zag G-weights and variations and combinations of these. Most of these examples suffer from several drawbacks including having a plethora of parts, requiring close tolerances, and having limited accuracy and reliability.
It has been found desirable to combine the higher reliability and accuracy of electronics for timing and control functions for the safety afforded by mechanical obstruction of a firing train. By doing so, major improvements in performance, reliability, and producibility are provided.
Therefore, there arises a need for a mechanical S&A device for arming the explosive projectile, which may be used in combination with an electronic timing and logic device. Further, there arises a need for an S&A device which prevents fuze arming prior to sensing a credible launch event, prevents arming while in-bore, and prevents aligning the firing train until safe separation from the gun tube is achieved. Such device should also provide a degree of modularity so that it can be used in both electrical and mechanical fuze environments. The present invention directly addresses and overcomes the shortcomings of the prior art.